| 摘要 |
PURPOSE:To attain stably and surely track jump with simple operation by setting a point of time when acceleration drive is transited to decelerating drive by a driving voltage generating circuit based on a zero cross poing obtained by a zero cross point detecting circuit. CONSTITUTION:When a jump instruction signal J is given, an accelerating voltage Vac is generated from a driving voltage generating circuit 1 and applied to a tracking actuator 2, then a head is moved from a tracking position TG to an adjacent tracking position TN. When the actuator 2 approaches a tracking position TO at the intermediate position and an output voltage of a zero cross detecting circuit 9 changes from a high level H to a low level L, the driving voltage generating circuit 1 generates a decelerating voltage Vde having opposite polarity and the level goes down gradually. Further, when an output of a characteristic approximation circuit 5 reaches zero level. the tracking actuator 2 reaches the objective tracking position TN. |
